Aligned carbon nanotube-based electronics on glass wafer.

Carbon nanotubes (CNTs), due to excellent electronic properties, are emerging as a promising semiconductor for diverse electronic applications with superiority over silicon. However, until now, the supposed superiority of CNTs by "head-to-head" comparison within a well-defined voltage range remains unrealized. Here, we report aligned CNT (ACNT)-based electronics on a glass wafer and successfully develop a 250-nm gate length ACNT-based field-effect transistor (FET) with an almost identical transfer curve to a "90-nm" node silicon device, indicating a three- to four-generation superiority. Moreover, a record gate delay of 9.86 ps is achieved by our ring oscillator, which exceeds silicon even at a lower supply voltage. Furthermore, the fabrication of basic logic gates indicates the potential for further digital integrated circuits. All of these results highlight ACNT-based FETs on the glass wafer as an effective solution/platform for further development of CNT-based electronics.

Wafer-Scale Carbon Nanotubes Diodes Based on Dielectric-Induced Electrostatic Doping.

Diodes based on p-n junctions are fundamental building blocks for numerous circuits, including rectifiers, photovoltaic cells, light-emitting diodes (LEDs), and photodetectors. However, conventional doping techniques to form p- or n-type semiconductors introduce impurities that lead to Coulomb scattering. When it comes to low-dimensional materials, controllable and stable doping is challenging due to the feature of atomic thickness. Here, by selectively depositing dielectric layers of Y2O3 and AlN, direct formation of wafer-scale carbon-nanotube (CNT) diodes are demonstrated with high yield and spatial controllability. It is found that the oxygen interstitials in Y2O3, and the oxygen vacancy together with Al-Al bond in AlN/Y2O3 electrostatically modulate the intrinsic CNTs channel, which leads to p- and n-type conductance, respectively. These CNTs diodes exhibit a high rectification ratio (>104) and gate-tunable rectification behavior. Based on these results, we demonstrate the applicability of the diodes in electrostatic discharge (ESD) protection and photodetection.

Improving Carbon Nanotube-Based Radiofrequency Field-Effect Transistors by the Device Architecture and Doping Process.

The semiconducting carbon nanotube (CNT) has been considered a promising candidate for future radiofrequency (RF) electronics due to its excellent electrical properties of high mobility and small capacitance. After decades of development, great progress has been achieved on CNT-based RF field-effect transistors (FETs). However, almost all elevations are owing to advancement of the CNT materials and fabrication process, while the study of device architecture is seldom considered and reported. In this work, we innovatively combined device architecture and related doping processes to further optimize CNT-based RF FETs by guiding process or materials with collaborative optimization for the first time and explore their effect on device performance carefully and statistically. Based on more mature random-oriented CNT materials, we fabricated CNT-based RF FETs having three different gate positions of device architecture variation accompanied by suitable doping schemes. The optimized FETs obtained 2-3 times of current density (transconductance) and 1.3 times the cutoff frequency and maximum oscillation frequency compared with unoptimized devices at the same channel length. After transistor-level verification of effect, we further built a CNT RF amplifier and demonstrated almost 10 dB of transducer gain improvement operating at 8 GHz for X-band application. The achieved results from this work would help further improve CNT RF performance beyond the materials and process point of view.

Polyphyllin II (PPII) Enhances the Sensitivity of Multidrug-resistant A549/DDP Cells to Cisplatin by Modulating Mitochondrial Energy Metabolism.

BACKGROUND/AIM: Cisplatin resistance often leads to treatment futility and elevated mortality rates in patients with lung cancer. One promising strategy to address this challenge involves the integration of traditional Chinese medicine (TCM) with chemotherapeutic drugs. Currently, the potential synergistic effect and underlying mechanism of polyphyllin II (PPII) and cisplatin combination in combating cisplatin (DDP) resistance in lung cancer remain unexplored. MATERIALS AND METHODS: In this study, we established a cisplatin resistance model using A549 cells and explored the underlying mechanisms of PPII in combination with cisplatin in A549/DDP resistant cells. Specifically, we assessed the impact of PPII combined with cisplatin on A549/DDP cell proliferation, viability, and the expression of apoptosis-related proteins. To gain deeper insights into the underlying mechanism, we examined the effects of PPII and cisplatin on mitochondrial function in A549/DDP cells. RESULTS: This combination induced cell cycle arrest at both the S phase and G2/M phase in A549/DDP cells, thereby promoting apoptosis. Western blotting confirmed that DDP acted synergistically with PPII to enhance the expression of apoptotic proteins, diminish the expression of anti-apoptotic proteins, and promote the expression of anti-proliferation proteins in the mitochondrial pathway of A549/DDP cells. CONCLUSION: The combination of PPII and cisplatin effectively modulated the mitochondrial function, thereby reversing drug resistance in A549/DDP cells. This innovative combination therapy shows significant promise as a novel strategy for overcoming cisplatin resistance in lung cancer.

Unzipping Carbon Nanotubes to Sub-5-nm Graphene Nanoribbons on Cu(111) by Surface Catalysis.

Graphene nanoribbons (GNRs) are promising in nanoelectronics for their quasi-1D structures with tunable bandgaps. The methods for controllable fabrication of high-quality GNRs are still limited. Here a way to generate sub-5-nm GNRs by annealing single-walled carbon nanotubes (SWCNTs) on Cu(111) is demonstrated. The structural evolution process is characterized by low-temperature scanning tunneling microscopy. Substrate-dependent measurements on Au(111) and Ru(0001) reveal that the intermediate strong SWCNT-surface interaction plays a pivotal role in the formation of GNRs.

High-Performance Carbon Nanotube Thin-Film Transistor Technology.

Semiconducting single-walled carbon nanotubes (CNTs) have ideal electronic, chemical, and mechanical properties and are ideal channel materials for constructing transistors in the post-Moore era. Experiments have shown that CNT-based planar CMOS transistors can be scaled down to sub-10 nm technology nodes, demonstrating excellent performance far exceeding the silicon limit. At the same time, CNT electronic technology is essentially a thin-film transistor technology, which enables the construction of chips on such substrates as glass and polymers with an area of several meters, providing technical support for large-area and flexible electronic applications. In addition, since CNT electronics technology involves only low-temperature processes (less than 400 °C), the monolithic 3D integration of logic and memory devices can be realized which can greatly improve the comprehensive performance of the chip and lead to a thousand-fold performance increase for special data structures, especially in AI applications.

Role of MicroRNAs in Dietary Interventions for Obesity and Obesity-Related Diseases.

Obesity and related metabolic syndromes pose a serious threat to human health and quality of life. A proper diet is a safe and effective strategy to prevent and control obesity, thus maintaining overall health. However, no consensus exists on the connotations of proper diet, and it is attributed to various factors, including "nutritional dark matter" and the "matrix effect" of food. Accumulating evidence confirms that obesity is associated with the in vivo levels of miRNAs, which serve as potential markers and regulatory targets for obesity onset and progression; food-derived miRNAs can regulate host obesity by targeting the related genes or gut microbiota across the animal kingdom. Host miRNAs mediate food nutrient-gut microbiota-obesity interactions. Thus, miRNAs are important correlates of diet and obesity onset. This review outlines the recent findings on miRNA-mediated food interventions for obesity, thereby elucidating their potential applications. Overall, we provide new perspectives and views on the evaluation of dietary nutrition, which may bear important implications for dietary control and obesity prevention.

Hederagenin Induces Apoptosis of Human Hepatoma HepG2 Cells via the Mitochondrial Pathway.

OBJECTIVE: The objective of this study is to assess the antitumor effects of hederagenin (HDG) in liver cancer (LC) cells and explore the related mechanisms. METHODS AND MATERIALS: HepG2 cells were treated with HDG and cisplatin, respectively. The CCK8 assay was used to detect cell activity, DAPI staining was used to detect the proportion of living cells, TUNEL assay to detect the proportion of apoptotic cells, flow cytometry to detect the membrane potential, fluoroscopic electron microscopy to detect microstructural changes to the mitochondrial, and western blot analysis and high-content screening to detect apoptosisrelated proteins. RESULTS: Treatment with HDG inhibited the growth of HepG2 cells, decreased the proportion of viable cells, increased the proportion of apoptotic cells, and significantly increased the proportion of cells in the G1 phase. Fluorescence staining showed that HDG damaged the mitochondria of HepG2 cells and significantly decreased the number of mitochondria. Flow cytometry showed that HDG decreased the mitochondrial membrane potential of HepG2 cells. Observations by electron microscopy showed that HDG caused swelling and vacuole formation of the mitochondria of HepG2 cells. HDG significantly reduced the average fluorescence intensity of Bcl-2 in HepG2 cells and significantly increased that of the pro-apoptosis proteins Bax, Cytochrome-c, and Caspase-3. CONCLUSION: HDG induced apoptosis of HepG2 cells via the mitochondrial pathway.

Single-walled carbon nanotubes synthesized by laser ablation from coal for field-effect transistors.

Single-walled carbon nanotubes (SWCNTs) have been attracting extensive attention due to their excellent properties. We have developed a strategy of using coal to synthesize SWCNTs for high performance field-effect transistors (FETs). The high-quality SWCNTs were synthesized by laser ablation using only coal as the carbon source and Co-Ni as the catalyst. We show that coal is a carbon source superior to graphite with higher yield and better selectivity toward SWCNTs with smaller diameters. Without any pre-purification, the as-prepared SWCNTs were directly sorted based on their conductivity and diameter using either aqueous two-phase extraction or organic phase extraction with PCz (poly[9-(1-octylonoyl)-9H-carbazole-2,7-diyl]). The semiconducting SWCNTs sorted by one-step PCz extraction were used to fabricate thin film FETs. The transformation of coal into FETs (and further integrated circuits) demonstrates an efficient way of utilizing natural resources and a marvelous example in green carbon technology. Considering its short steps and high feasibility, it presents great potential in future practical applications not limited to electronics.

Univariable and multivariable mendelian randomization study revealed the modifiable risk factors of urolithiasis.

BACKGROUND: Urolithiasis is a common urological disease with increasing incidence worldwide, and preventing its risk poses significant challenges. Here, we used Mendelian randomization (MR) framework to genetically assess the causal nature of multifaceted risk factors on urolithiasis. METHODS: 17 potential risk factors associated with urolithiasis were collected from recently published observational studies, which can be categorized basically into lifestyle factors and circulating biomarkers. The instrumental variables of risk factors were selected from large-scale genome-wide association studies (N ≤ 607,291). Summary-level data on urolithiasis were obtained from UK Biobank (UKB) (3,625 cases and 459,308 noncases) and the FinnGen consortium (5,347 cases and 213,445 noncases). The univariable and multivariable MR analyses were applied to evaluate the causal, independent effect of these potential risk factors upon urolithiasis. Effects from the two consortia were combined by the meta-analysis methods. RESULTS: Higher genetically predicted sex hormone-binding globulin (SHBG, OR, 0.708; 95% CI, 0.555 to 0.903), estradiol (OR, 0.179; 95% CI, 0.042 to 0.751), tea intake (OR, 0.550; 95% CI, 0.345 to 0.878), alcoholic drinks per week (OR, 0.992; 95% CI, 0.987 to 0.997), and some physical activity (e.g., swimming, cycling, keeping fit, and bowling, OR, 0.054; 95% CI, 0.008 to 0.363) were significantly associated with a lower risk of urolithiasis. In the Multivariate Mendelian Randomization (MVMR) analyses, the significant causal associations between estradiol, SHBG, tea intake, and alcoholic drinks per week with urolithiasis were robust even after adjusting for potential confounding variables. However, the previously observed causal association between other exercises and urolithiasis was no longer significant after adjusting for these factors. CONCLUSIONS: The univariable and multivariable MR findings highlight the independent and significant roles of estradiol, SHBG, tea intake, and alcoholic drinks per week in the development of urolithiasis, which might provide a deeper insight into urolithiasis risk factors and supply potential preventative strategies.

High-Speed Carbon Nanotube Photodetectors for 2 µm Communications.

In the era of big data, the growing demand for data transmission capacity requires the communication band to expand from the traditional optical communication windows (∼1.3-1.6 µm) to the 2 µm band (1.8-2.1 µm). However, the largest bandwidth (∼30 GHz) of the current high-speed photodetectors for the 2 µm window is considerably less than the developed 1.55 µm band photodetectors based on III-V materials or germanium (>100 GHz). Here, we demonstrate a high-performance carbon nanotube (CNT) photodetector that can operate in both the 2 and 1.55 µm wavelength bands based on high-density CNT arrays on a quartz substrate. The CNT photodetector exhibits a high responsivity of 0.62 A/W and a large 3 dB bandwidth of 40 GHz (setup-limited) at 2 µm. The bandwidth is larger than that of existing photodetectors working in this wavelength range. Moreover, the CNT photodetector operating at 1.55 µm exhibits a setup-limited 3 dB bandwidth over 67 GHz at zero bias. Our work indicates that CNT photodetectors with high performance and low cost have great potential for future high-speed optical communication at both the 2 and 1.55 µm bands.

An Ultrathin Flexible Programmable Spin Logic Device Based on Spin-Orbit Torque.

Flexible electronic devices have shown increasingly promising value facilitating our daily lives. However, flexible spintronic devices remain in their infancy. Here, this research demonstrates a type of nonvolatile, low power dissipation, and programmable flexible spin logic device, which is based on the spin-orbit torque in polyimide (PI)/Ta/Pt/Co/Pt heterostructures fabricated via capillary-assisted electrochemical delamination. The magnetization switching ratio is shown to be about 50% for the flexible device and does not change after 100 cycles of bending, indicating the device has stable performance. By designing the path of pulse current, five Boolean logic gates AND, NAND, NOT, NOR, and OR can be realized in an integrated two-element device. Moreover, such peeling-off devices can be successfully transferred to almost any substrate, such as paper and human skin, and maintain high performance. The flexible PI/Ta/Pt/Co/Pt spin logic device serves as logic-in-memory architecture and can be used in wearable electronics.

Amplification-Free Detection of SARS-CoV-2 Down to Single Virus Level by Portable Carbon Nanotube Biosensors.

The rapid and sensitive detection of trace-level viruses in a simple and reliable way is of great importance for epidemic prevention and control. Here, a multi-functionalized floating gate carbon nanotube field effect transistor (FG-CNT FET) based biosensor is reported for the single virus level detection of SARS-CoV-2 virus antigen and RNA rapidly with a portable sensing platform. The aptamers functionalized sensors can detect SARS-CoV-2 antigens from unprocessed nasopharyngeal swab samples within 1 min. Meanwhile, enhanced by a multi-probe strategy, the FG-CNT FET-based biosensor can detect the long chain RNA directly without amplification down to single virus level within 1 min. The device, constructed with packaged sensor chips and a portable sensing terminal, can distinguish 10 COVID-19 patients from 10 healthy individuals in clinical tests both by the RNAs and antigens by a combination detection strategy with an combined overall percent agreement (OPA) close to 100%. The results provide a general and simple method to enhance the sensitivity of FET-based biochemical sensors for the detection of nucleic acid molecules and demonstrate that the CNT FG FET biosensor is a versatile and reliable integrated platform for ultrasensitive multibiomarker detection without amplification and has great potential for point-of-care (POC) clinical tests.

Silicon Waveguide-Integrated Carbon Nanotube Photodetector with Low Dark Current and 48 GHz Bandwidth.

Low-dimensional materials with excellent optoelectronic properties and complementary metal-oxide-semiconductor (CMOS) process compatibility have the potential to construct high-performance photodetectors used in a cost-efficient monolithic or hybrid integrated optical communication system. Carbon nanotubes (CNTs) have attracted a lot of attention due to special geometric structure and broad band response, high optical absorption coefficient, ps-level intrinsic light response, high carrier mobility and wafer-scaled production process. Here, we demonstrated a high-performance waveguide-integrated CNT photodetector with asymmetric palladium (Pd) and hafnium (Hf) contact electrodes. The ideal photodetector structure was realized via comparing with simulation and experimental results, where the optimized device achieved a high 3 dB bandwidth ∼48 GHz at 0 V, as well as a responsivity ∼73.62 mA/W and dark current ∼0.157 µA at -2 V bias voltage. This waveguide-integrated CNT photodetector with low dark current and high bandwidth is helpful for next-generation optical communication and high-speed optical interconnects.

Ballistic two-dimensional InSe transistors.

The International Roadmap for Devices and Systems (IRDS) forecasts that, for silicon-based metal-oxide-semiconductor (MOS) field-effect transistors (FETs), the scaling of the gate length will stop at 12 nm and the ultimate supply voltage will not decrease to less than 0.6 V (ref. 1). This defines the final integration density and power consumption at the end of the scaling process for silicon-based chips. In recent years, two-dimensional (2D) layered semiconductors with atom-scale thicknesses have been explored as potential channel materials to support further miniaturization and integrated electronics. However, so far, no 2D semiconductor-based FETs have exhibited performances that can surpass state-of-the-art silicon FETs. Here we report a FET with 2D indium selenide (InSe) with high thermal velocity as channel material that operates at 0.5 V and achieves record high transconductance of 6 mS µm-1 and a room-temperature ballistic ratio in the saturation region of 83%, surpassing those of any reported silicon FETs. An yttrium-doping-induced phase-transition method is developed for making ohmic contacts with InSe and the InSe FET is scaled down to 10 nm in channel length. Our InSe FETs can effectively suppress short-channel effects with a low subthreshold swing (SS) of 75 mV per decade and drain-induced barrier lowering (DIBL) of 22 mV V-1. Furthermore, low contact resistance of 62 Ω µm is reliably extracted in 10-nm ballistic InSe FETs, leading to a smaller intrinsic delay and much lower energy-delay product (EDP) than the predicted silicon limit.

Improving the Performance of Aligned Carbon Nanotube-Based Transistors by Refreshing the Substrate Surface.

An aligned semiconducting carbon nanotube (A-CNT) array has been considered an excellent channel material to construct high-performance field-effect transistors (FETs) and integrated circuits (ICs). The purification and assembly processes to prepare a semiconducting A-CNT array require conjugated polymers, introducing stubborn residual polymers and stress at the interface between A-CNTs and substrate, which inevitably affects the fabrication and performance of the FETs. In this work, we develop a process to refresh the Si/SiO2 substrate surface underneath the A-CNT film by wet etching to clean the residual polymers and release the stress. Top-gated A-CNT FETs fabricated with this process show significant performance improvement especially in terms of saturation on-current, peak transconductance, hysteresis, and subthreshold swing. These improvements are attributed to the increase in carrier mobility from 1025 to 1374 cm2/Vs by 34% after the substrate surface refreshing process. Representative 200 nm gate-length A-CNT FETs exhibit an on-current of 1.42 mA/µm and a peak transconductance of 1.06 mS/µm at a drain-to-source bias of 1 V, subthreshold swing (SS) of 105 mV/dec, and negligible hysteresis and drain-induced barrier lowering (DIBL) of 5 mV/V.

Isolation and purification of Tartary buckwheat polysaccharides and their effect on gut microbiota.

Tartary buckwheat (Fagopyrum tataricum) is rich in polysaccharides that can be utilized by the gut microbiota (GM) and provide several health benefits. However, the mechanisms underlying the action of these polysaccharides remain unclear to date. In this study, Tartary buckwheat polysaccharides (TBP) were purified, and five fractions were obtained. The composition of these fractions was determined using ion chromatography. Different TBP components were investigated regarding their probiotic effect on three species of Bifidobacteria and Lactobacillus rhamnosus. In addition, the effect of TBP on GM and short-chain fatty acids (SCFAs) was evaluated. Results showed that the probiotic effect of TBP fraction was dependent on their composition. The polysaccharides present in different fractions had specific probiotic effects. TBP-1.0, mainly composed of fucose, glucose, and d-galactose, exhibited the strongest proliferation effect on L. rhamnosus, while TBP-W, rich in glucose, d-galactose, and fructose, had the best promoting effect on Bifidobacterium longum and Bifidobacterium adolescentis growth. Furthermore, TBP-0.2, composed of d-galacturonic acid, d-galactose, xylose, and arabinose, exhibited its highest impact on Bifidobacterium breve growth. The composition of GM was significantly altered by adding TBP during fecal fermentation, with an increased relative abundance of Lactococcus, Phascolarctobacterium, Bacteroidetes, and Shigella. Simultaneously, the level of SCFA was also significantly increased by TBP. Our findings indicate that Tartary buckwheat can provide specific dietary polysaccharide sources to modulate and maintain GM diversity. They provide a basis for Tartary buckwheat commercial utilization for GM modulation.

Sex-specific differences in the association between metabolically healthy overweight/obesity and the risk of hypertension in Chinese ethnic minorities.

OBJECTIVE: To estimate and compare sex-specific differences between metabolically healthy overweight/obesity (MHOO) and the risk of hypertension among Dong, Bouyei, and Miao adults in southwest China. METHODS: MHOO was diagnosed when the patient had a body mass index ≥24 kg/m2 and the presence of ≤1 component of metabolic syndrome. The main outcome was the occurrence of hypertension after the diagnosis or measurement by a physician at the baseline survey. Multivariate logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) between MHOO and the risk of hypertension. RESULTS: We enrolled 16,433 Chinese Dong, Bouyei, and Miao adults. Using the metabolically healthy normal weight (MHNW) as a reference and after adjusting for confounders, the association between MHOO and the risk of hypertension was stronger in Dong (OR = 1.46, 95% CI: 1.07-2.00) and Miao (OR = 2.05, 95% CI: 1.48-2.85) men and did not exist in Bouyei men (OR = 1.14, 95% CI: 0.81-1.60). After adjusting for the age, the association between MHOO and the risk of hypertension was stronger in men than in women among Dong adults aged 30-59 years (OR = 1.64, 95% CI: 1.12-2.40) and did not differ between men and women among Dong adults aged 60-79 years or among Miao or Bouyei adults. CONCLUSION: The results of this study demonstrated sex-specific differences in the association between MHOO and the risk of hypertension and that sex-specific differences further differed among Dong, Bouyei, and Miao adults.

Ultra-Strong Comprehensive Radiation Effect Tolerance in Carbon Nanotube Electronics.

Carbon nanotube (CNT) field-effect transistors (FETs) have been considered ideal building blocks for radiation-hard integrated circuits (ICs), the demand for which is exponentially growing, especially in outer space exploration and the nuclear industry. Many studies on the radiation tolerance of CNT-based electronics have focused on the total ionizing dose (TID) effect, while few works have considered the single event effects (SEEs) and displacement damage (DD) effect, which are more difficult to measure but may be more important in practical applications. Measurements of the SEEs and DD effect of CNT FETs and ICs are first executed and then presented a comprehensive radiation effect analysis of CNT electronics. The CNT ICs without special irradiation reinforcement technology exhibit a comprehensive radiation tolerance, including a 1 × 104 MeVcm2 mg-1 level of the laser-equivalent threshold linear energy transfer (LET) for SEEs, 2.8 × 1013 MeV g-1 for DD and 2 Mrad (Si) for TID, which are at least four times higher than those in conventional radiation-hardened ICs. The ultrahigh intrinsic comprehensive radiation tolerance will promote the applications of CNT ICs in high-energy solar and cosmic radiation environments.